4io_10key.lst

4个IO接10个按键的扫描方法,按这个方法8个IO可以接成36个按键

C51 COMPILER V8.12   4IO_10KEY                                                             05/24/2008 17:53:04 PAGE 1   


C51 COMPILER V8.12, COMPILATION OF MODULE 4IO_10KEY
OBJECT MODULE PLACED IN 4io_10key.OBJ
COMPILER INVOKED BY: d:\Keil\C51\BIN\C51.EXE 4io_10key.c BROWSE DEBUG OBJECTEXTEND

line level    source

   1          /**************************************
   2          *                                                                         *
   3          *       4个IO接10个按键                                   *
   4          *                                                                         *
   5          ***************************************/
   6          #include <reg51.h>
   7          #include <intrins.h>
   8          
   9          #define uchar unsigned char
  10          #define uint  unsigned int
  11          #define ulong unsigned long
  12          
  13          sbit KeyPort0 =P2^0; 
  14          sbit KeyPort1 =P2^1;
  15          sbit KeyPort2 =P2^2;
  16          sbit KeyPort3 =P2^3;
  17          
  18          sbit LED1=P1^0;
  19          sbit LED2=P1^1;
  20          sbit LED3=P1^2;
  21          sbit LED4=P1^3;
  22          sbit LED5=P1^4;
  23          sbit LED6=P1^5;
  24          sbit LED7=P1^6;
  25          sbit LED8=P1^7;
  26          //-------------------------------------------------------------------------------
  27          unsigned char KeyScan()
  28          {
  29   1              uchar _keyvalue;
  30   1              P2 |= 0xff;
  31   1              _keyvalue=0;
  32   1              
  33   1              if( !KeyPort0 )
  34   1                      _keyvalue = 1;
  35   1              else if( !KeyPort1 )
  36   1                      _keyvalue = 2;
  37   1              else if( !KeyPort2 )
  38   1                      _keyvalue = 3;
  39   1              else if( !KeyPort3 )
  40   1                      _keyvalue = 4;
  41   1              else
  42   1              {
  43   2                      KeyPort0 =0;
  44   2                      if( !KeyPort1 )
  45   2                              _keyvalue = 5;
  46   2                      else if( !KeyPort2 )
  47   2                              _keyvalue = 6;
  48   2                      else if( !KeyPort3 )
  49   2                              _keyvalue = 7;
  50   2                      else
  51   2                      {
  52   3                              KeyPort1 =0;
  53   3                              if( !KeyPort2 )
  54   3                                      _keyvalue = 8;
  55   3                              else if( !KeyPort3 )
C51 COMPILER V8.12   4IO_10KEY                                                             05/24/2008 17:53:04 PAGE 2   

  56   3                                      _keyvalue = 9;
  57   3                              else
  58   3                              {
  59   4                                      KeyPort2 =0;
  60   4                                      if( !KeyPort3 )
  61   4                                              _keyvalue = 10;
  62   4                              }
  63   3                      }
  64   2              } 
  65   1              return _keyvalue; 
  66   1      }
  67          //-------------------------------------------------------------------------------
  68          void main ()
  69          {
  70   1              while(1)
  71   1              {
  72   2                      switch(KeyScan())
  73   2                      {
  74   3                              case   1:  P1=0x01;  break;//key1 00
  75   3                              case   2:  P1=0x02;  break;//key2 01
  76   3                              case   3:  P1=0x04;  break;//key3 02
  77   3                              case   4:  P1=0x08;  break;//key4 03                            
  78   3                              case   5:  P1=0x10;  break;//key5 04
  79   3                              case   6:  P1=0x20;  break;//key6 05
  80   3                              case   7:  P1=0x40;  break;//key7 06
  81   3                              case   8:  P1=0x80;  break;//key8 07                                    
  82   3                              default:   break;       
  83   3                      }
  84   2              }
  85   1      }


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    167    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----    ----
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  0 WARNING(S),  0 ERROR(S)